The Effects of Jasmonic Acid and Chemicals in the JA Pathway on the Defense Systems and Gene Expression in Moss, Physcomitrella patens and Amblystegium serpens

Systemic acquired resistance (SAR) is a defense system used by plants that results in increased resistance to future pathogen infection following an initial pathogen exposure. SAR in vascular plants has been well documented; however, a similar defense system has only recently been documented in non-vascular plants. It is believed that chemicals in the jasmonic acid (JA) pathway are able to activate the SAR response in vascular plants. The non-vascular plant, Amb/ystegium serpens, will be used as a model to test if SAR is triggered by JA and two other molecules in the JA pathway, 12-oxo-phytodieonic acid, and methyl jasmonate. To test whether or not SAR has been put into effect, A. serpens will be inoculated with the fungal pathogen Pythium irregu/are after initial hormone application. A second moss species, Physcomitrella patens, will be used for analysis of gene expression after fungal elicitor or hormone application. This research will further develop our understanding about the systemic defense response in nonvascular plants, and will aid in our understanding of the evolution of this important mechanism